Research Results

Hydrogen can be produced by splitting water using renewable energy sources such as sunlight and wind, and it has the characteristic of not emitting carbon dioxide when used as energy. However, because storage and transportation are difficult, research into "hydrogen carriers"—substances that can efficiently store and transport hydrogen—is actively being conducted. Formic acid has attracted attention as one of the promising candidate substances for these hydrogen carriers. Nevertheless, hydrogen production via formic acid decomposition using conventional catalysts requires the use of strongly acidic formic acid, and there was a further challenge where controlling the reaction after adding the catalyst was difficult. To resolve this issue, Professor Amao and his colleagues constructed a coupled system combining a biocatalytic process using formate dehydrogenase derived from Candida boidinii with a photoredox reaction utilizing water-soluble zinc porphyrin, methyl viologen, and colloidal platinum nanoparticles dispersed with polyvinylpyrrolidone. Through this system, they succeeded in producing hydrogen from an aqueous formate solution in the neutral region, controllable via visible light. Using this system, the conversion rate from formate to hydrogen reached approximately 92% after 25 hours of irradiation. This research utilizes sunlight and contributes to the improvement of hydrogen production technologies.

Comment from Professor Amao:
"The cover art of this paper visualizes the production process of green hydrogen using sunlight."